package com.ibeetl.code.ch05;

import org.openjdk.jmh.annotations.*;
import org.openjdk.jmh.runner.Runner;
import org.openjdk.jmh.runner.RunnerException;
import org.openjdk.jmh.runner.options.Options;
import org.openjdk.jmh.runner.options.OptionsBuilder;

import java.util.concurrent.TimeUnit;

/**
 * swtich 优化
 *
 * @author 公众号 java系统优化
 */
@BenchmarkMode(Mode.Throughput)
@Warmup(iterations = 5)
@Measurement(iterations = 5, time = 1, timeUnit = TimeUnit.SECONDS)
@Threads(1)
@Fork(1)
@OutputTimeUnit(TimeUnit.MILLISECONDS)
@State(Scope.Benchmark)
public class SwitchStringTest {
    String key = "e";

    @Benchmark
    public void testStringSwitch() {
        String c;
        switch (key) {
            case "key":
                c = key;
                break;
            case "b":
                c = key;
                break;
            case "c":
                c = key;
                break;
            case "e":
                c = key;
                break;
            case "h":
                c = key;
                break;

        }

    }

    @Benchmark
    public void testString2IntSwitch() {
        String c;
        switch (key.hashCode()) {
            case 97: { //a
                c = key;
                break;
            }
            case 98: { //b
                c = key;
                break;
            }
            case 99: { //c
                c = key;
                break;
            }
            case 101: { //e
                c = key;
                break;
            }
            case 104: { //h
                c = key;
                break;
            }

        }
    }


    public static void main(String[] args) throws RunnerException {
        Options opt = new OptionsBuilder()
            .include(SwitchStringTest.class.getSimpleName())
            .forks(1)
            .build();
        new Runner(opt).run();
    }
}
